If the function $j(x)$ is defined only on domain $[-1,2]$, and is defined on this domain by the formula
\(j(x) = 2x^2 + 7\)
then what is the range of $j(x)$? Express your answer as an interval or as a union of intervals.
y = 2x^2 + 7
This is a parabola that turns upward and has its vertex at (0, 7)
The max of the function occurs at x = 2 and equals 2(2)^2 + 7 = 15
So......the range is [7 , 15 ] on the given interval